You could sacrifice the following:
knife -.5 (take a razor blade - .1oz.) = .4oz saved
wind jacket (drop and take only rain jacket) -4.1
take just 1meter of duct tape. 2m is a lot. -.15oz.
two lights? just take the Micro. -.5
lip balm - .34
replace these 2 with: dermatone stick [+.15oz worn, (https://www.dermatone.com/store/pc/viewPrd.asp?idcategory=5&idproduct=17) if you are wearing long clothing and a tilley, then you don't need much more sunscreen but for your ears, neck, and back of hands, right?] = 0.24 oz. saved
Total saved: 10.75oz.